YMCA gym membership is ~ $50 per month and you can use the showers and hot tub as much as you want. Some areas have low income discounts. There are also "day rooms" or drop in centers that provide free shower and laundry facilities for unsheltered folks.
Most Sikh temples serve a free vegetarian meal every day (langar). All are welcome and there is no religious component or requirement to attend religious services.
Food banks will typically provide food that needs prepping- bag of potatoes, a frozen chicken, a carton of eggs. Soup kitchens provide prepared meals (but may require you to attend religious services).
Many cities offer "safe parking" programs. They are areas where you are allowed to sleep in your vehicle without being bothered by the cops and have a portable restroom and running water. Space can be limited though.